Bob Boone -- 1980 World Series champion and father of Yankees manager Aaron Boone -- has died ... the middle link in baseball's first-ever three-generation family.

His eldest son, former MLB star Bret Boone, announced the news on social media early Tuesday morning. No cause of death was shared.

The Boones made history in 1992, when Bret debuted in the bigs ... making them the first family with three generations of Major Leaguers. Bob's dad, Ray Boone, was a two-time All-Star infielder who played for six teams from 1948 to 1960. Aaron followed his brother to the majors in 1997.

And some people around the game saw it coming. During a 1981 playoff broadcast, with 12-year-old Bret and 8-year-old Aaron shagging balls with their dad's team, NBC's Dick Enberg said, "There's never been three generations to make it to the major leagues, but they say the Boones might well be the first."

Bob's own career was LEGIT. The San Diego native and Stanford grad was a sixth-round pick by the Phillies in 1969, switched from third base to catcher in the minors, and went on to make four All-Star teams and win seven Gold Gloves across 19 seasons with Philly, the California Angels and the Kansas City Royals.

His biggest moment came in 1980 ... he hit .412 in the World Series and caught the final pitch as the Phillies won their first-ever title, all while playing on a foot he said he'd broken in the NLCS.

Boone retired in 1990 after catching 2,225 games, third-most all time. He later managed the Royals and Cincinnati Reds -- Aaron Boone was on his team -- and spent years in the Washington Nationals' front office, picking up another ring in 2019.

Tributes poured in Tuesday. Mike Piazza said watching Boone in the '70s Phillies made him want to become a catcher. Old teammate Greg Luzinski called Boone his former roommate and close friend. And Jim Bowden, who hired Boone to manage the Reds, called him a "high class and character special human."

Brett once summed up his dad's honesty perfectly ... "Bob Boone will go through a yellow light and call the police on himself."

In retirement near San Diego, Bob and his wife, Sue Boone, built their days around their kids' and grandkids' games ... and Aaron called his dad on the drive home after nearly every game at Yankee Stadium.